The basic idea, https://github.com/CreativeMD/LittleTiles/blob/1.12/src/main/java/com/creativemd/littletiles/common/api/te/ILittleTileTE.java

if(te instanceof ILittleTileTE)
{
try
{
VoxelBlob blob = ((ILittleTileTE) te).getVoxelBlob(force);
}catch(Exception){
//Something went wrong
}
}

Should work as of bc51f04